A man whose ex-girlfriend is charged with killing his 4-year-old son in Missouri says he left his child in her care while he went to Chicago to visit his ailing mother.

Quatavia Givens, the boy's caretaker and his father's ex-girlfriend, was charged Wednesday afternoon in the boy's death. She faces first degree child abuse resulting in a death.

Police announced the arrest after finding the boy's body Tuesday morning.

Darnell Gray would have turned five on Tuesday, said Kijuanis Gray, the boy's father.

"He liked to smile, he liked to be goofy. He loved to run around with me. He loved to play basketball. It's a lot," Gray said of his son.

Gray said he is no longer with Darnell's mother, who lives in Chicago. He moved to Missouri a few years ago because he "wanted a better life" for himself and his son, and brought his son to Missouri six months ago.

Recently, however, Gray returned to Chicago to visit his sick mother and asked his then-girlfriend to watch his son. Givens is now in custody.

"I trusted her to watch him. But I wasn't expecting her to do this to him," Gray said.

Police said Givens called authorities at about 7 a.m. Oct. 25, saying the boy was missing when she woke up. After investigating, police later learned that the boy was likely missing hours before she called police, and their investigative efforts led them to his body.